Index: channels/chan_sip.c
===================================================================
--- channels/chan_sip.c	(revision 263582)
+++ channels/chan_sip.c	(working copy)
@@ -12304,37 +12304,38 @@
 		ao2_t_unlink(peers_by_ip, peer, "ao2_unlink of peer from peers_by_ip table");
 	}
 
-	/* Check that they're allowed to register at this IP */
-	/* XXX This could block for a long time XXX */
-	/*! \todo Check NAPTR/SRV if we have not got a port in the URI */
-	hp = ast_gethostbyname(host, &ahp);
-	if (!hp)  {
-		ast_log(LOG_WARNING, "Invalid host '%s'\n", host);
-		ast_string_field_set(peer, fullcontact, "");
-		ast_string_field_set(pvt, our_contact, "");
-		return PARSE_REGISTER_FAILED;
-	}
-	memcpy(&testsin.sin_addr, hp->h_addr, sizeof(testsin.sin_addr));
-	if (ast_apply_ha(sip_cfg.contact_ha, &testsin) != AST_SENSE_ALLOW ||
-			ast_apply_ha(peer->contactha, &testsin) != AST_SENSE_ALLOW) {
-		ast_log(LOG_WARNING, "Host '%s' disallowed by contact ACL (violating IP %s)\n", host, ast_inet_ntoa(testsin.sin_addr));
-		ast_string_field_set(peer, fullcontact, "");
-		ast_string_field_set(pvt, our_contact, "");
-		return PARSE_REGISTER_DENIED;
-	}
-
-	/*! \todo This could come before the checking of DNS earlier on, to avoid
-		DNS lookups where we don't need it... */
 	if (!ast_test_flag(&peer->flags[0], SIP_NAT_FORCE_RPORT) && !ast_test_flag(&peer->flags[0], SIP_NAT_RPORT_PRESENT)) {
+		/* use the data provided in the Contact header for call routing */
+		ast_debug(1, "Store REGISTER's Contact header for call routing.\n");
+		/* XXX This could block for a long time XXX */
+		/*! \todo Check NAPTR/SRV if we have not got a port in the URI */
+		hp = ast_gethostbyname(host, &ahp);
+		if (!hp)  {
+			ast_log(LOG_WARNING, "Invalid host '%s'\n", host);
+			ast_string_field_set(peer, fullcontact, "");
+			ast_string_field_set(pvt, our_contact, "");
+			return PARSE_REGISTER_FAILED;
+		}
 		peer->addr.sin_family = AF_INET;
 		memcpy(&peer->addr.sin_addr, hp->h_addr, sizeof(peer->addr.sin_addr));
 		peer->addr.sin_port = htons(port);
 	} else {
 		/* Don't trust the contact field.  Just use what they came to us
 		   with */
+		ast_debug(1, "Store REGISTER's src-IP:port for call routing.\n");
 		peer->addr = pvt->recv;
 	}
 
+	/* Check that they're allowed to register at this IP */
+	memcpy(&testsin.sin_addr, &peer->addr.sin_addr, sizeof(testsin.sin_addr));
+	if (ast_apply_ha(sip_cfg.contact_ha, &testsin) != AST_SENSE_ALLOW ||
+			ast_apply_ha(peer->contactha, &testsin) != AST_SENSE_ALLOW) {
+		ast_log(LOG_WARNING, "Host '%s' disallowed by contact ACL (violating IP %s)\n", host, ast_inet_ntoa(testsin.sin_addr));
+		ast_string_field_set(peer, fullcontact, "");
+		ast_string_field_set(pvt, our_contact, "");
+		return PARSE_REGISTER_DENIED;
+	}
+
 	/* if the Contact header information copied into peer->addr matches the
 	 * received address, and the transport types are the same, then copy socket
 	 * data into the peer struct */